It’s a first-of-its-kind study. The largest and longest study ever done shows the promising long-term effects “brain games” have on slowing Alzheimer’s and dementia. The study was released Monday from the New England Research Institute.

Eighty-four-year-old Clint Butcher loves to listen to the classical music he once played. He no longer plays or sings. He rarely speaks. And the man who was still water skiing into his 60s now has trouble even matching colors and numbers in the card game UNO.

"Don't get me crying,” Karen Allen said. “First of all, you go through that stage where you become the caregiver as your parents once took care of you. And I think you go through a transition of, ‘This isn't the parent that I knew.’"

Allen watched her mother suffer with Alzheimer's, and is now her dad's primary caregiver as he struggles with stage 3 dementia. Six of his eight siblings have similar symptoms.

But a new, long-term study shows “brain games” (specifically, problem-solving games involving letter and number patterns) and games that require quick recognition of images on screens can help slow the progression.

The study's co-author says “brain training” preserved cognitive function in three-quarters of those tested - helping an 80-year-old function more like a 70-year-old.

Although the games do not prevent dementia, they do seem to slow its arrival. It’s promising to caregivers like Allen, who watch their loved ones deteriorate every day.

"He wouldn't know who you were if you went in and met him, walked out of the room and then walked back in,” Allen said. “He wouldn't know you."

Home Instead’s Alicia Harvey said it’s comforting that studies are being done to help Alzheimer’s patients’ quality of living.

"Since there are so many increased cases at this point, it's good to know they're looking for at least ways to treat the symptoms of it so someone can have a longer quality of life," Harvey said.